This invention relates generally to the desalination of salt water, by solar energy means, and particularly to an installation for the desalination of salt water, which has no moving parts requiring energy input to prime movers such as, for example, mechanical pumps or electrical pumps for the pumping and circulation of salt water during the desalination process. Such installations can be used with advantage close to coasts, lagoons and salt lakes.
In installations of this type an important design criterion for the system is that the cycle of operations involved in the desalination of salt water should be completely passive, that is one which requires no input of energy for circulating the salt water used for the desalination process. In practice a certain minimum energy input has been required in most prior art systems. Another design criterion is that of minimizing the auxiliary components of the system in order to reduce first cost.
The systems known in the art, however, have many disadvantages, particularly with regard to the use made of the incoming radiant energy inasmuch as a considerable amount of incident energy is not effectively utilized during the condensation phase of the salt water vapour. In known systems a large proportion of the incident radiant energy is lost from the installation when the water vapor, which condenses on the covering glass area, returns to this all the heat of vaporization, which represents the greater part of the thermal energy involved in the process.